Optical signals in an optical network are impacted by different sources of noise during their propagation from a source to a destination. Optical impairments can be categorized into three main types: (1) added noise from the optical amplification process (e.g., noise due to Amplified Spontaneous Emission (ASE)); (2) noise sources external to amplifiers and not dependent on signal power; and (3) non-linear noise, dependent on per channel signal power.
Impairments due to amplification noise and non-linear noise depend on the “working point” that has been selected for a specific system. A “working point” refers to and is based on per channel power and amplifier gain, which in turn is related to the noise optimization of an Erbium-doped Fiber Amplifier (EDFA). Noise optimization of an optical amplifier is generally managed during the design phase. However, after the design phase and once the optical network is deployed, network conditions can occur that may necessitate changes to one or more optical amplifiers in the network.